Unifire&reg;Wired vertical mouse Superior Ergonomic Design mice 5 Buttons optical usb health mouse for Alleviate Wrist Fatigue Vertical Mouse Optical Mouse Mice Ergonomic Design Gaming Mouse (black) Ergonomically designed to reduce strain. Prevention of mouse hand. Five Button,Full Function Mouse. Premium-level quality and confort for the price of a conventional mouse. You pick the hand position that best suits you.Plug and play,compatible with Mac and PC. Button: 4 buttons in default / 1 scroll wheel (middle button).